Breast Cancer Drug Tamoxifen Appears To Raise Risk Of Developing New Type Of Tumor, Study Finds

Breast cancer patients taking a long-term course of the estrogen-blocker tamoxifen, which has been used widely to prevent recurrences of hormone-sensitive breast cancer, might have four times the risk of developing "an uncommon but aggressive" new tumor that is not estrogen-sensitive, according to a new study published Tuesday in the journal Cancer Research, the New York Times reports.